Inductive charging coil device

ABSTRACT

An inductive charging coil device, in particular a hand-held power tool inductive charging coil device, includes at least one coil unit and at least one core unit. It is provided that the core unit is at least partially formed by microscopic core elements embedded in a binder.

FIELD OF THE INVENTION

The present invention is directed to an inductive charge coil device, inparticular a hand-held power tool inductive charging coil device,including at least one coil unit and at least one core unit.

BACKGROUND INFORMATION

Inductive charging coil devices, in particular hand-held power toolinductive charging coil devices, including at least one coil unit and atleast one core unit are known.

SUMMARY OF THE INVENTION

The present invention is directed to an inductive charge coil device, inparticular a hand-held power tool inductive charging coil device,including at least one coil unit and at least one core unit.

It is provided that the core unit be at least partially formed bymicroscopic core elements embedded in a binder. A “coil unit” is to beunderstood in this context in particular as a unit which has at leastone conductor loop including at least one winding formed by a conductor.The coil unit is provided to transmit and/or to receive electricalenergy in at least one operating state. The coil unit may have a windingsupport. The winding support may be provided in particular to supportthe at least one conductor loop. The coil unit may be provided to supplyreceived energy, in particular via a voltage transformer and/or chargingelectronics, to a consumer and/or a cell unit of a rechargeable battery.Alternatively, the hand-held power tool inductive charging coil devicemay be provided to transmit energy to a further inductive charging coildevice. The coil unit may be provided to convert an electric alternatingcurrent into a magnetic alternating field and/or vice versa. Inparticular, the inductive charging coil device may form an inductiveenergy transmission system with a further inductive charging coildevice. The alternating field may have a frequency of 10 kHz-500 kHz,particularly 100 kHz-120 kHz. A “hand-held power tool inductive chargingcoil device” is to be understood in this context in particular as aninductive coil charging device of a hand-held power tool, a hand-heldpower tool rechargeable battery, or a hand-held power tool rechargeablebattery charging device. A “hand-held power tool” is to be understood inthis context as an electrical device which is hand-operated by a user,such as, in particular, a power drill, a drill hammer, a saw, a plane, ascrewdriver, a milling tool, a grinder, an angle grinder, and/or amultifunction tool, or a garden tool such as a hedge trimmer, and shruband/or grass shears.

A “core unit” is to be understood in this context in particular as adevice which is provided to focus an electromagnetic alternating field.In particular, the core unit may be formed at least partially by amagnetic material. A “magnetic material” may be to be understood in thiscontext as a ferromagnetic, in particular magnetically soft, material.Alternatively, it is also conceivable to use ferromagnetic and/orantiferromagnetic materials. A “core element” is to be understood inthis context in particular as integral parts of the core unit which areat least essentially responsible for the magnetic properties of the coreunit. The core elements may be at least predominantly formed by themagnetic material. “Microscopic” is to be understood in this context inparticular as a core element, the largest extension of which is lessthan 1 mm, which may be less than 0.1 mm, particularly less than 0.01mm. In particular, the microscopic core elements may be formed as apowder of a magnetic material. A “binder” is to be understood in thiscontext in particular as a binder which is provided to form what may bean integrally joined bond with the core elements. Binder and coreelements may form a composite material. The binder may be formed by aplastic material, such as, in particular, a thermoplastic or syntheticresin. The core elements may be admixed to the binder, so that the coreunit may be produced by a casting process and/or an injection moldingprocess. Alternatively, the core elements may be molded using thebinder. The core elements may be potted using the binder and/or the coreelements may be at least partially coated using the binder. The coreunit may have a trough, in which the core elements are potted using thebinder. Alternatively, the core unit may be demolded from the troughafter the potting, so that the trough may be used for casting multiplecore units. The core elements may be potted in a binder implemented as acasting resin, in particular an epoxy resin.

Alternatively, the binder may contain linearly polymerizing monomerbuilding blocks and/or oligomer building blocks of a thermoplastic suchas lactams and/or cyclic oligomers of butylene terephthalate. The bindermay enclose the core elements and polymerize to form a polymer, such as,in particular, a polyamide. This operation may take place more rapidlythan curing of an epoxy resin. Manufacturing and/or curing of the coreunit may take place in a particularly short time span. Manufacturing ofthe core unit may be particularly simple. In particular, the core unitmay be manufactured in a desired shape by a casting and/or injectionmolding process. The core unit may be formed by original molds.Post-processing of the core unit may be omitted or may be particularlysimple. The binder may be particularly fracture-resistant. The core unitmay be particularly tough and fracture-resistant. The core unit may beparticularly durable in relation to mechanical stresses, in particularin comparison to a core unit formed by a sintering material in asintering process. Shattering of the core unit may be made moredifficult. A service life and/or a level of robustness of the core unitmay be particularly long or high, respectively.

Alternatively, it is provided that the core unit has a plurality of coreelements, which are at least partially formed by sintered pieces. A“sintered piece” is to be understood in this context in particular as afragment and/or granule of a sintered material, in particular a sinteredferrite material. The sintered pieces may be at least 70%,advantageously at least 80%, particularly advantageously at least 90%formed by a manganese-zinc (MnZn) and/or nickel-zinc (NiZn) sinteredmaterial. The sintered pieces may particularly advantageously havemagnetic properties. The sintered pieces may have an irregular fragmentshape. The core unit may at least essentially have the advantageousproperties of a core unit formed by a sintered ferrite material. Inparticular, magnetic losses may be low. The core unit may have a highpermeability. A relative permeability μ of the core unit may be, atleast in partial areas of the core unit, greater than 100, which may begreater than 1000, particularly greater than 5000.

The core unit may be particularly cost-effective. In particular, thecore unit may be more cost-effective than a core unit which is formed byone sintered piece and/or a small number of sintered pieces. A “small”number is to be understood in this context as a number less than 50,which may be less than 25, particularly less than 10. The core elementsmay be potted using the binder. The binder may form a particularlyfracture-resistant unit with the core elements, in particular a fractureresistance may be higher than in the case of a core unit which is formedby one sintered component. Alternatively, the core elements may belacquered over, i.e., coated, using a binder implemented as a lacquer.The core elements may stick to one another. Particularly little bindermay be required. Cavities between the core elements may remain at leastpartially free. The core unit may have a particularly low mass. Thebinder may contain additional microscopic core elements. The magneticproperties of the core unit may be improved further. Large-area and/orlarge-volume core units may be formed particularly easily. Shrinking ofsintered components may be neglected. A setpoint geometry of the coreunit may be ensured particularly easily. The sintered pieces mayparticularly be formed by fragments of recycled sintered components, inparticular core units.

Damaged and/or obsolete core units may advantageously be reused and formcore elements of the core unit according to the present invention.Resources may be saved. The sintered pieces may be cost-effective. Thecore elements may have a mean diameter which corresponds to at most ⅔ ofa core height. A “core height” is to be understood in this context inparticular as a height of the core unit in the direction of the windingaxis of the coil unit. In the case of a core unit having areas ofdiffering height, the “core height” may be to be understood as thesmallest height of the core unit. It may be effectively ensured that thecore elements are situated inside the core height during themanufacturing of the core unit. Core elements may be prevented fromprotruding out of the core.

Furthermore, it is provided that the core unit has a core jacket, whichis provided for fixing the core elements. A “core jacket” is to beunderstood in this context in particular as an envelope which envelopsthe core elements. In particular, the core jacket may be formed by afilm and/or a thin-walled elastomeric and/or thermoplastic material. Thecore unit may be formed by deep drawing a thermoplastic film on one orboth sides, the thermoplastic film enclosing the core elements.Alternatively, the core elements may be shrink-wrapped in a core jacketformed by shrinkable tubing. In another embodiment of the presentinvention, the core elements may be enveloped by film tubing, which issealed by a hot sealing method. A binder may be omitted. Furthermore,the core elements may be fixed in a core jacket by vacuum packing thecore jacket. Furthermore, a stabilizing arrangement may be situatedinside the core jacket, which holds the core jacket and the coreelements essentially in setpoint geometry. The core elements haverounded edges in particular. Alternatively, the core jacket could beimplemented as sufficiently stable. The core elements of the core unitmay be held by the core jacket in a setpoint geometry and/or a desiredspatial arrangement. The core elements may have an at least restrictedmobility inside the core jacket. The core unit may be flexible and/ormoldable. A shape of a core unit formed by core elements enveloped in acore jacket may be adapted during assembly of the inductive chargingcoil device.

Furthermore, it is provided that the core unit has areas having adiffering core material composition. A “core material composition” is tobe understood in this context in particular as a chemical and/orphysical composition of core materials forming an area of the core unit,such as, in particular, a composition of magnetic materials and bindersforming the area of the core unit. An “area” is to be understood in thiscontext in particular as an integrally joined, coherent area of the coreunit, in particular a layer of the core unit. A volume of an area isadvantageously at least 5%, which may be at least 10%, particularly atleast 15% of a total volume of the core unit. The core materialcomposition may be adapted particularly well to various requirementswithin the core unit. In particular, the core material composition, inareas which have a high field strength during operation of the coilunit, may be particularly well suitable for focussing a magnetic field.The core material composition in areas having a high mechanical stress,such as in the area of a bearing arrangement, which is provided forsupporting the core unit, may be particularly fracture-resistant. Thecore unit may be particularly cost-effective in areas without specialrequirements. Those skilled in the art may select the core materialcomposition optimally in particular with regard to functional costs andmaterial costs. The core unit may be particularly efficient and/ordurable and/or cost-effective.

Furthermore, it is provided that the core unit has at least two corematerials, which have differing permeabilities. The core unit may havedifferent types of magnetic materials and/or core elements, which areeach made of a material or a material mixture having a differingpermeability. Core elements and binders may have differentpermeabilities. The magnetic properties of the core unit may be adaptedparticularly well.

In one particularly advantageous embodiment of the present invention, itis provided that the core unit has at least two core materials, whichhave differing densities and/or moduli of elasticity. In particular, thedensities and/or the moduli of elasticity of magnetic materials and/orcore elements and/or binders may differ. Areas of the core unit whichare particularly at risk of fracture may be formed at leastpredominantly by a particularly elastic core material. Less stressedareas of the core unit and/or areas of the core unit which have a lowmagnetic field strength during operation may be formed by a corematerial having a particularly low density. The core unit may beparticularly fracture-resistant. The core unit may have a particularlylow mass. Furthermore, it is provided that at least one area of the coreunit is at least essentially formed by air. In particular, the core unitmay have at least one air layer and/or at least one air entrapment. Inparticular, areas of the core unit which have a low magnetic fieldstrength during operation may have air entrapments and/or air layers.The core unit may have a particularly low mass. The core unit may beparticularly cost-effective. Particularly little core material may benecessary for manufacturing the core unit.

Furthermore, it is provided that at least two areas having a differingcore material composition in a thickness direction of the core unit formlayers situated adjacent to one another. A “thickness direction” of thecore unit is to be understood in this context in particular as thedirection of the core unit, in which the core unit has the smallestextension. The thickness direction is advantageously at leastessentially the direction of a winding axis of the coil unit. A “windingaxis” is to be understood in this context in particular as an axis whichextends in the middle through a center of the windings of the conductorloops of the at least one coil unit of the inductive charging coildevice. “At least essentially” is to be understood in this context inparticular to mean a deviation of less than 10°, which may be less than5°. A “layer” is to be understood in this context in particular as acoherent planar area, which extends perpendicularly to the thicknessdirection over more than 80%, which may be more than 90% of the coreunit.

The layers of the core unit facing toward the coil unit mayadvantageously have a core material composition having a particularlyhigh permeability and/or having a particularly large proportion ofmagnetic materials. Layers of the core unit facing away from the coilunit may advantageously have a particularly fracture-resistant and/orlight and/or cost-effective core material composition. The core unit mayhave particularly advantageous magnetic and/or mechanical properties.Furthermore, it is provided that at least two areas having a differingcore material composition are integrally joined to one another. One areamay advantageously be implemented as a coating of another area. Inparticular, a layer of a core material having a particularly highpermeability may be applied in a coating method to a layer of a corematerial having a lower permeability, which is used as a carrier layer.The coating may be supported particularly well by the carrier layer. Thecore unit may be particularly robust.

Furthermore, it is provided that at least two areas having a differingcore material composition are situated radially around the winding axisof the coil unit. The areas may advantageously be situated at leastessentially in the shape of a cylinder and/or hollow cylinder around thewinding axis. “At least essentially” is to be understood in this contextas a deviation of a volume distribution of less than 20%, which may beless than 10%, from a cylinder and/or hollow cylinder shape around thewinding axis. Advantageously, areas which are situated in the directionof the winding axis adjacent to the windings of the coil unit and/orareas which have a particularly small distance to the windings may havea core material composition having a particularly high permeabilityand/or having a particularly large proportion of magnetic materials.Areas which are situated in a radius around the windings inside oroutside the windings may advantageously have a particularlyfracture-resistant and/or light and/or cost-effective core materialcomposition. The core unit may have particularly advantageous magneticand/or mechanical properties. In one particularly advantageousembodiment of the present invention, it is possible that areas aresituated radially and in layers, a permeability of the areasadvantageously decreasing with increasing distance from the windings ofthe coil unit. Areas are also conceivable, whose core materialcomposition and/or permeability changes continuously, in particular,their permeability decreases continuously with increasing distance fromthe windings. The magnetic properties of the core unit may beparticularly advantageous.

Furthermore, it is provided that the core unit at least essentially hasa plate-shaped or trough-shaped configuration. The core unit may have anextension which corresponds to at least a diameter of the conductorloops of the coil unit around a winding axis. A “winding axis” is to beunderstood in this context in particular as an axis which extends in themiddle through a center of the windings of the conductor loops of the atleast one coil unit of the inductive charging coil device. The core unitmay cover the coil unit at least essentially without recesses. The coreunit may focus a magnetic alternating field particularly effectively inthe area of the coil unit.

Furthermore, it is provided that the core elements have a mean diameterwhich corresponds to at most ⅔ of a core height. A “core height” is tobe understood in this context in particular as a height of the core unitin the direction of the winding axis of the coil unit. In a core unithaving areas having differing heights, the “core height” may beunderstood as the smallest height of the core unit. It may beeffectively ensured that the core elements are situated within the coreheight during the manufacturing of the core unit. Core elements may beprevented from protruding out of the core.

Furthermore, it is provided that the inductive charging coil device hasa housing unit, into which the core unit is cast and/or injectionmolded. A “housing unit” is to be understood in this context inparticular as a housing, which at least essentially encloses at leastthe coil unit and the core unit. The housing unit may be an integralpart of a hand-held power tool rechargeable battery charging device. Thehousing unit may be an integral part of a hand-held power toolrechargeable battery pack and/or a hand-held power tool. “Cast” is to beunderstood in this context in particular as integrally joined and/orembedded by enveloping using a casting compound. “Injection molded” isto be understood in this context in particular as a method in which acore material forming the core unit after solidification or a corematerial mixture forming the core unit is molded on the housing unitand/or injected into the housing unit in a liquid and/or plastic statein a casting method, in particular an injection molding method.

The core unit may be particularly effectively connected to the housingunit. The housing unit may protect the core unit particularly well, inparticular from mechanical influences. Breaking of the core unit may beprevented. The core unit may be supported particularly securely on thehousing unit. Further components for supporting the core unit on thehousing unit may be omitted. The inductive charging coil device may beparticularly robust and/or cost-effective. An electronics unit may be atleast partially cast jointly with the core unit and/or at leastpartially embedded in the core unit. The electronics unit isadvantageously cast into the core unit and/or embedded in the core unitby more than 50%, which may be by more than 80%, particularlycompletely. An “electronics unit” is to be understood in this context inparticular as a device which has at least one electrical and/orelectronic component. The electronics unit may advantageously havecharging electronics of the hand-held power tool rechargeable batterypack and/or the hand-held power tool rechargeable battery chargingdevice. The electronics unit and the core unit may be moved into thereceptacle area and cast jointly. The electronics unit and the core unitmay particularly be connected permanently to the housing unit. Theelectronics unit and the core unit may be protected particularly wellfrom environmental influences, in particular from moisture and/orcontaminants. In one alternative embodiment of the present invention,the electronics unit may be embedded in the core unit. “Embedded” is tobe understood in this context in particular to mean that the core unitentirely or partially encloses the electronics unit.

In particular, the electronics unit may be extrusion coated and/orembedded using the core material forming the core unit and/or the corematerial mixture forming the core unit. After solidification, the coreunit may form a unit with the electronics unit. The core unit mayprotect the electronics unit particularly well. Core unit andelectronics unit may be situated particularly compactly in the housingunit. Furthermore, it is provided that the coil unit is cast at leastpartially jointly with the core unit and/or is embedded at leastpartially in the core unit. The coil unit is advantageously cast intothe core unit and/or embedded in the core unit by more than 50%, whichmay be by more than 80%, particularly completely. In particular, thecoil unit may be cast with the core unit and/or embedded in the coreunit jointly with the electronics unit. The inductive charging coildevice including the core unit, the coil unit, and the electronics unitmay form a particularly robust unit with the housing unit. The inductivecharging coil device may be protected particularly well from soilingand/or moisture and/or vibrations. The inductive charging coil devicemay be particularly long-lasting.

Furthermore, it is provided that the housing unit has a pocket-likereceptacle area for the coil unit and/or the core unit and/or anelectronics unit, whereby a particularly simple assembly of the coildevice may be achieved. The coil unit and the core unit mayadvantageously be supported by the housing unit. A “pocket-likereceptacle area” is to be understood in particular as a receptacle areawhich forms a pocket in or on the housing. A “pocket” is to beunderstood in this context in particular as a subspace of the housingunit, which is implemented as at least essentially closed in particularat least in an operational state. “At least essentially” is to beunderstood in this context in particular to mean that more than 80%,which may be more than 90%, particularly more than 95% of an overallsurface of the receptacle area is implemented as closed. The receptaclearea advantageously has assembly openings, which may be closed by coversin an operational and/or assembled state.

In particular, the receptacle area may be delimited by an inner wall ofthe housing unit in the direction of a cell unit. A “cell unit” is to beunderstood in this context in particular as an energy storage unit,which has at least one rechargeable battery cell, which is provided inparticular for electrochemical storage of electrical energy. Therechargeable battery cell may be a lead rechargeable battery cell, aNiCd rechargeable battery cell, a NiMh rechargeable battery cell, but inparticular a lithium-based rechargeable battery cell. Further types ofrechargeable battery cells known to those skilled in the art are alsoconceivable. The coil device may be protected particularly well. Inparticular, the coil unit and/or the core unit and/or the electronicsunit and the cell unit may be spatially separated. A heat transferand/or a propagation of an electromagnetic alternating field from thearea of the coil unit and/or the core unit and/or the electronics unitinto adjoining areas, in particular in the direction of the cell unit,may be reduced. The receptacle area may accommodate the coil unit andthe core unit. An assembly may have the coil unit and the core unit. Anassembly of the coil device may be particularly simple. The coil unitand the core unit may be supported particularly securely by the housingunit.

It is provided that the receptacle area is provided to accommodate thecoil unit and/or the core unit and/or the electronics unit in aninsertion direction at least essentially in parallel to a main surfaceextension of the core unit and/or the electronics unit. “At leastessentially” is to be understood in this context in particular to mean adeviation of less than 10°, which may be less than 5°. The core unitand/or the electronics unit may be assembled particularly easily. Thereceptacle area may have at least one bearing unit, which is providedfor supporting the coil unit and/or the core unit and/or the electronicsunit. The bearing unit may leave a translation of the coil unit and/orthe core unit and/or the electronics unit free in the insertiondirection. In particular, the bearing unit may be formed by at least oneguide rail. The coil unit and/or the core unit and/or the electronicsunit may advantageously be introduced into the receptacle area byinsertion and supported by the bearing unit. The housing unit may havean assembly opening, through which the coil unit and/or the core unitand/or the electronics unit may be inserted in the insertion directioninto the receptacle area. The assembly opening may be closed by a coverelement. Assembly of the coil unit and/or the core unit and/or theelectronics unit may be particularly simple. Assembly material and/orfastening material may be omitted.

Furthermore, it is provided that main surfaces of the receptacle areaare at least essentially closed. In particular, the main surfaces may beat least essentially closed in an assembled, operational state of thecoil device. “At least essentially” is to be understood in this contextin particular to mean that the main surfaces are closed by more than75%, which may be by more than 90%, particularly by more than 95%. Themain surfaces may be closed by partition walls, which are part of thehousing unit. An electrical insulation and/or a mechanical protection ofthe coil unit and/or the core unit and/or the electronics unit may beimproved. Recesses of the receptacle area may be provided to receiveconnecting leads, to contact the coil unit with the cell unit. The cellunit may advantageously receive energy from the coil device.

Furthermore, a system having two inductive charging coil devices isprovided, in which the core unit of at least one of the inductivecharging coil devices has a plurality of core elements, which are formedat least partially by sintered pieces, whereby the core elements have amean diameter which is at least 10 μm multiplied by a ratio of a corediameter of the core unit divided by an air gap in at least oneoperating state of the inductive charging coil devices. In particular,one inductive charging coil device may be part of a hand-held power toolrechargeable battery pack and one inductive charging coil device may bepart of a hand-held power tool rechargeable battery charging device. An“air gap” is to be understood in this context as a distance of the twocore units in an operational arrangement of the two inductive chargingcoil devices in relation to one another. In particular, the air gapexists between the two core units when the hand-held power toolrechargeable battery pack is placed on the hand-held power toolrechargeable battery charging device, to charge the hand-held power toolrechargeable battery pack. The size of the air gap is established bythose skilled in the art during configuration of the hand-held powertool devices containing the inductive charging coil devices. The coreelements may advantageously have magnetic properties. Particularly smallcore elements may be used. The core elements may be particularlycost-effective. The core elements may be situated particularly well inthe core unit. The core elements may be situated particularly densely inthe core unit. A minimum size of the core elements may be ensured. Inparticular, the magnetic properties may be worse in the case of smallercore elements.

Furthermore, a method is provided for manufacturing a core unit havingthe described features. In particular, the method may include aplurality of core elements, which are microscopic and/or formed bysintered fragments, being introduced with a binder into a container andbeing potted or coated using the binder, and the binder subsequentlycuring to form a core unit. The container may subsequently be removed ormay remain part of the core unit. Alternatively, the method may includea plurality of core elements being enveloped by a packing material and,in a further step, a closed core jacket being formed by the packingmaterial around the core elements, by sealing the packing material byhot sealing or a core unit being formed by the packing material and thecore elements enclosed in the packing material in a deep drawingprocess. The core unit may be manufactured particularlycost-effectively. The core unit may be manufactured in a particularlylarge bandwidth of shapes and sizes. The core unit may be particularlyrobust and fracture-resistant.

Furthermore, a hand-held power tool device including a hand-held powertool inductive charging coil device having the described features isprovided. In this case, the hand-held power tool device may be formed bya hand-held power tool, a hand-held power tool rechargeable batterypack, a hand-held power tool case, or a hand-held power toolrechargeable battery charging device. The hand-held power tool devicemay have the above-mentioned advantages of the hand-held power toolinductive charging coil device.

Further advantages result from the following description of thedrawings. Exemplary embodiments of the present invention are shown inthe drawings. The drawings, the description, and the claims containnumerous features in combination. Those skilled in the art will alsoadvantageously consider the features individually and combine them toform further reasonable combinations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a core unit of an inductive chargingcoil device.

FIG. 2 shows a schematic view of a section through a hand-held powertool rechargeable battery pack including the inductive charging coildevice.

FIG. 3 shows a schematic sectional view of a core unit of an inductivecharging coil device in a second exemplary embodiment including aplurality of core elements formed by sintered fragments.

FIG. 4 shows a schematic sectional view through a hand-held power toolrechargeable battery pack including the inductive charging coil deviceof the second exemplary embodiment and a hand-held power toolrechargeable battery charging device including a further inductivecharging coil device.

FIG. 5 shows a schematic sectional view of an arrangement of the coreunit of the hand-held power tool rechargeable battery pack of the secondexemplary embodiment and a core unit of the hand-held power toolrechargeable battery charging device in relation to one another in anoperational state.

FIG. 6 shows a schematic sectional view of a manufacturing method of acore unit in a third exemplary embodiment.

FIG. 7 shows a schematic sectional view of the core unit of the thirdexemplary embodiment.

FIG. 8 shows a schematic sectional view of a hand-held power toolrechargeable battery pack including an inductive charging coil device ina fourth exemplary embodiment.

FIG. 9 shows a schematic sectional view of a coil unit and a core unitof an inductive charging coil device in a fifth exemplary embodiment.

FIG. 10 shows a schematic sectional view of a coil unit and a core unitof an inductive charging coil device in a sixth exemplary embodiment.

FIG. 11 shows a schematic sectional view of a hand-held power toolrechargeable battery pack including an inductive charging coil deviceand a hand-held power tool rechargeable battery charging deviceincluding a further inductive charging coil device in a seventhexemplary embodiment.

FIG. 12 shows a schematic view of a base part of the hand-held powertool rechargeable battery pack including the inductive charging coildevice of the seventh exemplary embodiment.

FIG. 13 shows a schematic view of a housing unit of a hand-held powertool rechargeable battery pack including an inductive charging coildevice in an eighth exemplary embodiment.

FIG. 14 shows a schematic sectional view of a core unit and a coil unitof an inductive charging coil device in a ninth exemplary embodiment.

FIG. 15 shows a schematic sectional view through a hand-held power toolrechargeable battery pack including the inductive charging coil deviceof the ninth exemplary embodiment and through a hand-held power toolrechargeable battery charging device including a further inductivecharging coil device.

FIG. 16 shows a schematic sectional view of a hand-held power toolrechargeable battery including an inductive charging coil device in atenth exemplary embodiment.

FIG. 17 shows a schematic sectional view through an electronics unit, acore unit, and a coil unit of the inductive charging coil device of thetenth exemplary embodiment.

FIG. 18 shows a schematic sectional view of the hand-held power toolrechargeable battery including the inductive charging coil device of thetenth exemplary embodiment and a hand-held power tool rechargeablebattery charging device including a further inductive charging coildevice.

FIG. 19 shows a schematic sectional view through an electronics unit, acore unit, and a coil unit of an inductive charging coil device in aneleventh exemplary embodiment.

DETAILED DESCRIPTION

FIG. 1 shows a core unit 14 a of a hand-held power tool inductivecharging coil device 10 a, which is formed by microscopic core elements24 a embedded in a binder 22 a. Core unit 14 a is provided for focussinga magnetic alternating field of a coil unit 12 a (FIG. 2). Core elements24 a are formed by a ferrite material. Core unit 14 a has a plate-shapedconfiguration. Core elements 24 a are implemented as a ferrite powder,the ferrite powder having a grain size of less than 0.1 mm. Coreelements 24 a are admixed to binder 22 a, which is formed by a castingresin. Core unit 14 a is manufactured in a casting process by castingthe mixture thus formed by binder 22 a and core elements 24 a.

FIG. 2 shows a section through a hand-held power tool rechargeablebattery pack 40 a including an inductive charging coil device 10 a. Acell unit 44 a is situated in a housing unit 42 a. Cell unit 44 a formsa hand-held power tool rechargeable battery, which is provided for anenergy supply of a hand-held power tool. Inductive charging coil device10 a is situated in housing unit 42 a on a side opposite cell unit 44 a.Proceeding from cell unit 44 a, inductive charging coil device 10 a hasa printed circuit board 96 a including charging electronics for cellunit 44 a. Plate-shaped core unit 14 a is situated adjoining printedcircuit board 96 a. Coil unit 12 a is situated adjoining core unit 14 a.Coil unit 12 a has a printed circuit board 52 a including printedconductors situated on both sides of a carrier layer 50 a. The printedconductors form two conductor loops having windings 98 a around awinding axis 56 a of coil unit 12 a, which are situated on both sides ofcarrier layer 50 a. Carrier layer 50 a exercises the function of awinding support of windings 98 a. Alternatively, windings may be made ofat least one litz wire wound onto a winding support. A contacting unit100 a guided through core unit 14 a connects printed circuit board 96 a,which includes charging electronics, to coil unit 12 a. Printed circuitboard 96 a including charging electronics is connected via a connectinglead 48 a to cell unit 44 a.

To charge cell unit 44 a, hand-held power tool rechargeable battery pack40 a is placed on a hand-held power tool rechargeable battery chargingdevice 72 a, which includes a similarly constructed inductive chargingcoil device 10′a. Hand-held power tool rechargeable battery chargingdevice 72 a has a current supply 74 a. If hand-held power toolrechargeable battery charging device 72 a is supplied with current, ahigh-frequency alternating current of 100 kHz flows through inductivecharging coil device 10′a, which is generated by charging electronicssituated on a printed circuit board 96′a. A magnetic alternating fieldis generated in a coil unit 12′a, which is focussed by a core unit 14′aand emitted essentially in the direction of inductive charging coildevice 10 a. A current, using which cell unit 44 a may be charged, isinduced in coil unit 12 a of inductive charging coil device 10 a.

The following description and the drawing of eleven further exemplaryembodiments are restricted essentially to the differences between theexemplary embodiments, reference fundamentally being able to be made tothe drawing and/or the description of the other exemplary embodimentswith respect to identically identified components, in particular inrelation to components having identical reference numerals. Todifferentiate the exemplary embodiments, instead of the letter a of thefirst exemplary embodiment, the letters b through k are added to thereference numerals of the further exemplary embodiments.

FIG. 3 shows a core unit 14 b of an inductive charging coil device 10 b(FIG. 4) in a second exemplary embodiment. Core unit 14 b has aplurality of core elements 16 b, which are formed by sintered fragments18 b. Furthermore, core unit 14 b has a binder 22 b and a trough 20 b.Core elements 16 b are fragments of a magnetic material formed by asintered ferrite material. In the present example, sintered fragments 18b are formed by a ferrite material, which contains MnZn and NiZncompounds and has a relative permeability μ>500.

Core elements 16 b are stacked in trough 20 b, which is provided foraccommodating core elements 16 b, and are potted using binder 22 b,which is formed by an epoxy resin. Binder 22 b additionally contains acomponent of powdered core elements 24 b. In one alternative embodiment,it is possible that binder 22 b only coats core elements 16 b with athin lacquer film and glues them to one another. Intermediate spacesbetween core elements 16 b are not completely filled with binder 22 b inthis case, so that air entrapments remain in core unit 14 b.

To manufacture core unit 14 b, core elements 16 b are distributed intrough 20 b in a first step. In a second step, binder 22 b is added,which cures in a third step. Subsequently, core unit 14 b may beinstalled in inductive charging coil device 10 b. Alternatively, afterthe curing of binder 22 b, trough 20 b may be removed and used tomanufacture further core units 14 b.

Core unit 14 b has an essentially plate-shaped configuration. Coreelements 16 b have a mean diameter 30 b, which is less than ⅔ of a coreheight 32 b (FIG. 5). It may thus be ensured that core elements 16 b aredistributed uniformly in core unit 14 b and core elements 16 b may beprevented from protruding out of core unit 14 b.

Inductive charging coil device 10 b is part of a hand-held power tooldevice 38 b (FIG. 4), which is implemented as a hand-held power toolrechargeable battery pack 40 b. A cell unit 44 b, which is provided tosupply a hand-held power tool with energy, into which hand-held powertool rechargeable battery pack 40 b may be inserted, is situated in ahousing unit 42 b. Hand-held power tool rechargeable battery pack 40 bhas a hand-held power tool rechargeable battery pack interface (notshown in greater detail here) for energy transfer to the hand-held powertool. Inductive charging coil device 10 b is provided for wirelessinductive energy transfer for a charging operation of cell unit 44 b.Inductive charging coil device 10 b is situated between cell unit 44 band a housing wall 46 b of housing unit 42 b. Proceeding from housingwall 46 b in the direction of cell unit 44 b, a coil unit 12 b, coreunit 14 b, and an electronics unit 58 b initially follow. Electronicsunit 58 b is connected with the aid of a connecting lead 48 b to cellunit 44 b and includes charging electronics for cell unit 44 b. Acontacting unit (not shown in greater detail here) connects coil unit 12b to electronics unit 58 b.

Coil unit 12 b is formed by a printed circuit board 52 b. Coil unit 12 bhas a conductor loop 54 b including a plurality of windings around awinding axis 56 b on both sides of a carrier layer 50 b of printedcircuit board 52 b. The windings of conductor loops 54 b have the samewinding direction. The windings are formed by the printed conductors oftwo conductor layers of printed circuit board 52 b situated on carrierlayer 50 b. Feed-throughs (not shown in greater detail) through carrierlayer 52 b have a connecting lead, which electrically connects the endsof the windings closest to winding axis 56 b, so that the two conductorloops 54 b form an electric coil. The ends of the windings remote fromwinding axis 56 b are connected to electronics unit 58 b.

A shielding unit, which is formed by a conductor layer 60 b, and whichcompletely covers electronics unit 58 b and cell unit 44 b viewed in thedirection of winding axis 56 b, is situated on the side of electronicsunit 58 b facing toward core unit 14 b. A magnetic alternating field inthe area of coil unit 12 b is in large part retroreflected in thedirection of coil unit 12 b by conductor layer 60 b, so that a fieldstrength in the area of cell unit 44 b and the side of electronics unit58 b facing toward cell unit 44 b, proceeding from conductor layer 60 b,is reduced.

If inductive charging coil device 10 b is subjected to the influence ofan electromagnetic alternating field, a current is induced in conductorloops 54 b of coil unit 12 b, which may be used to charge cell unit 50b. To generate the electromagnetic alternating field, a second,similarly constructed inductive charging coil device 10′b is provided,which is situated in a hand-held power tool rechargeable batterycharging device 72′b. Inductive charging coil device 10′b has anelectronics unit 58′b, which, from a current supplied via a currentsupply 74′b, generates an alternating current having a frequency of 100kHz and supplies a coil unit 12′b, so that the electromagneticalternating field is generated. If hand-held power tool rechargeablebattery pack 40 b is placed with housing wall 46 b on hand-held powertool rechargeable battery charging device 72′b, inductive charging coildevice 10 b thus enters the influence of the magnetic alternating fieldof inductive charging coil device 10′b, so that an energy transfer takesplace. A core unit 14′b is provided to focus the electromagneticalternating field generated by coil unit 12′b in the direction of coilunit 12 b of hand-held power tool rechargeable battery pack 40 b.

FIG. 5 shows the establishment of a minimal size of core elements 16 b.If hand-held power tool rechargeable battery pack 40 b is placed onhand-held power tool rechargeable battery charging device 72′b, it formsa system including the two inductive charging coil devices 10 b and10′b. The two core units 14 b, 14′b shown in FIG. 5 each have a diameter30 b, 30′b and core height 32 b, 32′b, which are identical in theexample shown. An air gap 36 b, which is defined by the mechanicalstructure of hand-held power tool rechargeable battery pack 40 b andhand-held power tool rechargeable battery charging device 72′b, existsbetween the two core units 14 b and 14′b. Air gap 36 b is to beunderstood as a spacing between the two core units 14 b and 14′b, inwhich further components are situated, in particular coil units 12 b and12′b and housing wall 46 b and a housing wall 46′b of hand-held powertool rechargeable battery charging device 72′b.

Core elements 16 b have mean diameter 30 b, which is at least 10 μmmultiplied by a ratio of a core diameter 34 b of core unit 14 b dividedby air gap 36 b in the operational state of inductive charging coildevices 10 b, 10′b. A smallest mean diameter 30′b of core elements 16′bis similarly established as a function of a core diameter 34′b and airgap 36 b.

FIGS. 6 and 7 show a manufacturing method of a core unit 14 c (FIG. 7)for operation with a coil unit 12 c in a third exemplary embodiment.Core unit 14 c of the third exemplary embodiment differs from core unit14 b of the second exemplary embodiment in particular in that core unit14 c has a core jacket 26 c, which is provided for fixing core elements16 c. Core elements 16 c, which are formed by sintered fragments 18 c,are situated between two layers of elastomeric material 80 c. Two molds78 c, which are heated by heating plates 76 c, are moved on both sidestoward the layers of elastomeric material 80 c, so that a vulcanizationprocess begins and core unit 14 c is formed. In core unit 14 c, coreelements 16 c are wrapped in an envelope made of elastomeric material 80c. Protruding ends 82 c of elastomeric material 80 c may be cut off in afurther step at cutting positions 84 c. Core unit 14 c thus formed has ahigh flexibility, since core elements 16 c are situated loosely in coreunit 14 c.

FIG. 8 shows a hand-held power tool rechargeable battery pack 40 dincluding an inductive charging coil device 10 d having a core unit 14 din a fourth exemplary embodiment. Core unit 14 d of the third exemplaryembodiment differs from core unit 14 b of the second exemplaryembodiment in particular in that core unit 14 d has a trough-shapedconfiguration. In particular, core unit 14 d completely encloses anelectronics unit 58 d around a winding axis 56 d and partially enclosesa cell unit 44 d around winding axis 56 d. Core unit 14 d forms ashielding unit of electronics unit 58 d and cell unit 44 d. A magneticfield, which impacts core unit 14 d from the direction of a coil unit 12d, is focussed by core unit 14 d and concentrated in the area of coilunit 12 d. A magnetic field strength is low on a side of core unit 14 dfacing away from coil unit 12 d, so that influences of the magneticalternating field on electronics unit 58 d and cell unit 44 d arereduced.

FIG. 9 shows a core unit 14 e and a coil unit 12 e of an inductivecharging coil device 10 e in a fifth exemplary embodiment. Core unit 14e of the fifth exemplary embodiment differs from the second exemplaryembodiment in particular in that core unit 14 e has areas 28 e having adiffering density of core elements 16 e. Core elements 16 e are formedby sintered fragments 18 e. Areas 28 e form layers 132 e, which aresituated adjacent to one another in a thickness direction 130 e, whichis oriented in a direction of a winding axis 56 e of conductor loops 54e of coil unit 12 e. An area of high density 86 e of core elements 16 efaces toward coil unit 12 e. In this area of high density 86 e, a fieldstrength of a magnetic alternating field is greatest during operation ofinductive charging coil device 10 e. An area of low density 90 e of coreelements 16 e is located on a side of core unit 14 e facing away fromcoil unit 12 e. A field strength of a magnetic alternating field islowest in this area of low density 90 e during operation of inductivecharging coil device 10 e. An area of moderate density 88 e of coreelements 16 e lies between areas of high density 86 e and low density 90e. Area of high density 86 e has a mean relative permeability μ=200,area of moderate density 88 e has a mean relative permeability μ=50, andarea of low density 90 e has a relative permeability μ=20. A proportionof a binder 22 e, which connects core elements 16 e, behaves in inverseproportion to the density of core elements 16 e. The quantity of coreelements 16 e required for manufacturing core unit 14 e isadvantageously reduced.

FIG. 10 shows a core unit 14 f and a coil unit 12 f of an inductivecharging coil device 10 f in a sixth exemplary embodiment. Core unit 14f of the sixth exemplary embodiment differs from the first exemplaryembodiment in particular in that core unit 14 f has areas 28 f having adiffering density of core elements 16 f. Core elements 16 f are formedby sintered fragments 18 f and are embedded in a binder 22 f. Areas 28 fare situated radially around a winding axis 56 f. An area of highdensity 86 f of core elements 16 f is situated adjoining conductor loops54 f of coil unit 12 f in the direction of winding axis 56 f. A fieldstrength of a magnetic alternating field is greatest in this area ofhigh density 86 f during operation of inductive charging coil device 10f. Areas of low density 90 f of core elements 16 f are located in anarea 28 f around a center 92 f of core unit 14 f and in an areaadjoining an edge 94 f of core unit 14 f. These areas of low density 90f have a large distance to conductor loops 54 f. A field strength of amagnetic alternating field is lowest in these areas of low density 90 fduring operation of inductive charging coil device 10 f. Areas ofmoderate density 88 f of core elements 16 f are located between areas ofhigh density 86 f and low density 90 f. In another embodiment of thepresent invention, it is possible that a distribution of areas 28 f ofdiffering density of core elements of the fifth and sixth exemplaryembodiments are combined, i.e., a density of core elements 16 f is afunction of a distance to conductor loop 54 f of coil unit 12 f bothaxially and also radially.

FIG. 11 shows a hand-held power tool device 38 g including an inductivecharging coil device 10 g and a further hand-held power tool device 38g′ including an inductive charging coil device 10′g in a seventhexemplary embodiment. Hand-held power tool device 38 g is implemented asa hand-held power tool rechargeable battery pack 40 g, and hand-heldpower tool device 38 g′ is implemented as a hand-held power toolrechargeable battery charging device 72′g. A cell unit 44 g, which isprovided to supply a hand-held power tool with energy, is situated in ahousing unit 42 g of hand-held power tool rechargeable battery pack 40g. Hand-held power tool rechargeable battery pack 40 g has a hand-heldpower tool rechargeable battery pack interface (not shown in greaterdetail) for contacting with the hand-held power tool. Inductive chargingcoil device 10 g is provided for wireless energy transfer for a chargingoperation of cell unit 44 g. Inductive charging coil device 10 g issituated between cell unit 44 g and a housing wall 46 g of a base part102 g of housing unit 42 g. Proceeding from housing wall 46 g in thedirection of cell unit 44 g, a coil unit 12 g, a core unit 14 g, and anelectronics unit 58 g initially follow. Electronics unit 58 g includescharging electronics, which is provided to charge cell unit 44 g.

Coil unit 12 g is formed by a disk-shaped printed circuit board 52 g.Printed circuit board 52 g has, on both sides of a carrier layer 50 g ofprinted circuit board 52 g, a conductor loop in each case includingwindings 98 g having a shared winding direction around a winding axis 56g. Windings 98 g are formed by printed conductors of printed circuitboard 52 g. A connecting lead (not shown in greater detail here)connects windings 98 g of the two conductor loops. Windings 98 gtherefore electrically form a coil of coil unit 12 g. Core unit 14 g,which is predominantly glued using a binder 22 g and is formed by coreelements 16 g formed by a sintered ferrite material, is also disk-shapedand has the same diameter as coil unit 12 g. A connecting lead 114 g,which is led through core unit 14 g, connects coil unit 12 g toelectronics unit 58 g. Electronics unit 58 g is connected with the aidof a connecting lead 48 g to cell unit 44 g.

Base part 102 g of housing unit 42 g has a trough-shaped receptacle area104 g, which is provided to accommodate core unit 14 g, coil unit 12 g,and electronics unit 58 g. Coil unit 12 g, core unit 14 g, andelectronics unit 58 g are inserted into a receptacle area 104 g andsubsequently potted using a potting compound 116 g. Alternatively, it ispossible that inductive charging coil device 10 g is formed in amulticomponent injection molding method, during which coil unit 12 g,core unit 14 g, and electronics unit 58 g are inserted into receptaclearea 104 g and subsequently extrusion coated using a thermoplastic.Connecting lead 48 g remains led out of inductive charging coil device10 g, so that it may subsequently be connected to cell unit 44 g. Acover element 106 g (FIG. 12), which is formed by a plastic plate,covers inductive charging coil device 10 g in receptacle area 104 g inrelation to cell unit 44 g.

Cover element 106 g has an electrically conductive material layer 110 g,which is formed by a graphite lacquer. Material layer 110 g forms ashielding unit 108 g, which is situated between coil unit 12 g and cellunit 44 g. Material layer 110 g has, in the case of a projection in thedirection of winding axis 56 g, a projection area 112 g, whichcompletely covers cell unit 44 g. Shielding unit 108 g shields cell unit44 g from influences of an electromagnetic alternating field occurringduring operation of inductive charging coil device 10 g.

If inductive charging coil device 10 g is subjected to the influence ofan electromagnetic alternating field, a current is induced in windings98 g of coil unit 12 g, which may be used for charging cell unit 44 g.Second, similarly constructed inductive charging coil device 10′g, whichis situated in hand-held power tool rechargeable battery charging device72′g, is provided for generating the electromagnetic alternating field.Inductive charging coil device 10′g has an electronics unit 58′g, whichgenerates an alternating current having a frequency of 100 kHz from acurrent supplied via a current supply 74′g and supplies a coil unit12′g, so that the electromagnetic alternating field is generated andfocussed by a core unit 14′g. If hand-held power tool rechargeablebattery pack 40 g is placed on hand-held power tool rechargeable batterycharging device 72′g, inductive charging coil device 10 g thus entersthe influence of the electromagnetic alternating field of inductivecharging coil device 10′g, so that an energy transfer takes place.

FIG. 13 shows a base part 102 h of a housing unit 42 h of a hand-heldpower tool rechargeable battery pack 40 h including an inductivecharging coil device 10 h in an eighth exemplary embodiment. Inductivecoil charging device 10 h of the eighth exemplary embodiment differsfrom inductive coil charging device 10 g of the seventh exemplaryembodiment in particular in that a coil unit 12 h and an electronicsunit 58 h are embedded in a core unit 14 h. Core unit 14 h is formed bycore elements 16 h embedded in a binder 22 h. Binder 22 h is formed byan epoxy resin. Core elements 16 h are formed by fragments of a sinteredferrite material. The core material composition made of binder 22 h andcore elements 16 h differs in areas 86 h, 90 h of core unit 14 h.

During manufacturing of inductive charging coil device 10 h, initiallycoil unit 12 h is introduced into a receptacle area 104 h of base part102 h. In a next step, a layer 118 h, which has core elements 16 h in ahigh density, is applied to coil unit 12 h. This layer 118 h forms anarea 86 h of core unit 14 h and has a relative permeability of μ=200.Layers 118 h, 120 h are situated adjacent to one another in a thicknessdirection 130 h of core unit 14 h, which is oriented in the direction ofa winding axis 56 h. Coil unit 12 h and core elements 22 h are pottedusing binder 22 h. A further layer 120 h is applied, which forms afurther area 90 h of core unit 14 h and has core elements 22 h in a lowdensity, which are also potted using binder 22 h. This layer 120 h has arelative permeability of μ=50. Subsequently, electronics unit 58 h isconnected to coil unit 12 h using a connecting lead 114 h, which is ledthrough layers 118 h, 120 h, and is also potted using binder 22 h.Inductive charging coil device 10 h forms a compact unit, which has acore unit 14 h, which is formed by binder 22 h and core elements 16 h,and into which electronics unit 58 h and coil unit 12 h are embedded. Onthe side of electronics unit 58 h facing toward coil unit 12 h, amaterial layer 110 h formed by a copper layer is situated, which forms ashielding unit 108 h. Material layer 110 h has a projection area 112 hin the direction of winding axis 56 h, which completely coverselectronics unit 58 h. Electronics unit 58 h is protected by shieldingunit 108 h from influences of an electromagnetic alternating field fromthe area of coil unit 12 h.

FIG. 14 shows a core unit 14 i and a coil unit 12 i of an inductivecharging coil device 10 i, which is shown in detail in FIG. 15, in aninth exemplary embodiment. Core unit 14 i has areas 28 i having adiffering core material composition. A first core material 124 i has amean relative permeability μ=50. A second core material 126 i is appliedto a side of core unit 14 i facing toward coil unit 12 i in a coatingmethod to first core material 124 i and has a mean relative permeabilityμ=200. Areas 28 i, which are formed by core materials 124 i, 126 i, areintegrally joined to one another. Areas 28 i form layers 132 i, whichare situated adjacent to one another in a direction 130 i, which isoriented in the direction of a winding axis 56 i of coil unit 12 i. On aside of core unit 14 i facing away from coil unit 12 i, it has a furtherarea 28 i, which is formed by air 128 i. A cover layer 134 i, which isformed by first core material 124 i, covers area 28 i formed by air 128i. Area 28 i formed by air 128 i has a mean relative permeability μ=20jointly with cover layer 134 i. Proceeding from the side facing towardcoil unit 12 i, relative permeability μ of the core unit decreases fromμ=200 to μ=20.

Inductive charging coil device 10 i is part of a hand-held power tooldevice 38 i (FIG. 15), which is implemented as a hand-held power toolrechargeable battery pack 40 i. A cell unit 44 i, which is provided tosupply a hand-held power tool with energy, into which hand-held powertool rechargeable battery pack 40 i may be inserted, is situated in ahousing unit 42 i. Hand-held power tool rechargeable battery pack 40 ihas a hand-held power tool rechargeable battery pack interface (notshown in greater detail here) for energy transfer to the hand-held powertool. Inductive charging coil device 10 i is provided for wirelessinductive energy transfer for a charging operation of cell unit 44 i.Inductive charging coil device 10 i is situated between cell unit 44 iand a housing wall 46 i of housing unit 42 i. Proceeding from housingwall 46 i in the direction of cell unit 44 i, coil unit 12 i core unit14 i, and an electronics unit 58 i initially follow. Electronics unit 58i is connected using a connecting lead 48 i to cell unit 44 i andincludes charging electronics for cell unit 44 i. A contacting unit (notshown in greater detail here) connects coil unit 12 i to electronicsunit 58 i.

Coil unit 12 i is formed by a printed circuit board 52 i. Printedcircuit board 52 i has, on both sides of a carrier layer 50 i, aconductor loop 54 i in each case including a plurality of windingsaround winding axis 56 i. The windings of conductor loops 54 i have thesame winding direction. The windings are formed by the printedconductors of two conductor layers of printed circuit board 52 i whichare situated on carrier layer 50 i. Feed-throughs (not shown in greaterdetail) through carrier layer 50 i have a connecting lead, whichelectrically connects the ends of the windings closest to winding axis56 i, so that the two conductor loops 54 i electrically form a coil. Theends of the windings remote from winding axis 56 i are connected toelectronics unit 58 i.

Core unit 14 i has a projection area 112 i, in the case of a projectionin the direction of winding axis 56 i, which completely coverselectronics unit 58 i and cell unit 44 i. A magnetic alternating fieldin the area of coil unit 12 i, which occurs during operation ofinductive charging coil device 10 i, is focussed by core unit 14 i inthe direction of coil unit 12 i. A magnetic field strength remains lowon a side of core unit 14 i facing toward electronics unit 58 i and cellunit 44 i, so that the field strength in the area of cell unit 44 i andelectronics unit 58 i is strongly reduced in relation to the fieldstrength in the area of coil unit 12 i. Core unit 14 i therefore forms ashielding unit for electronics unit 58 i and cell unit 44 i. A furthershielding unit may be omitted.

If inductive charging coil device 10 i is subjected to the influence ofa magnetic alternating field, a current is induced in conductor loops 54i of coil unit 12 i, which may be used to charge cell unit 44 i. Asecond, similarly constructed inductive charging coil device 10′i, whichis situated in hand-held power tool device 38 i implemented as hand-heldpower tool rechargeable battery charging device 72′i, is provided togenerate the magnetic alternating field. Inductive charging coil device10′i has an electronics unit 58′i, which generates an alternatingcurrent having a frequency of 100 kHz from a current supplied via acurrent supply 74′i and supplies a coil unit 12′i, so that the magneticalternating field is generated. If hand-held power tool rechargeablebattery pack 40 i is placed with housing wall 46 i on hand-held powertool rechargeable battery charging device 72′i, inductive charging coildevice 10 i thus enters the influence of the magnetic alternating fieldof inductive charging coil device 10′i, so that an energy transfer takesplace. A core unit 14′i is provided to focus the magnetic alternatingfield generated by coil unit 12′i in the direction of coil unit 12 i ofhand-held power tool rechargeable battery pack 40 i.

FIG. 16 shows a hand-held power tool device 38 j, which is implementedas a hand-held power tool rechargeable battery pack 40 j, including aninductive charging coil device 10 j. Inductive charging coil device 10 jhas a coil unit 12 j, a core unit 14 j, and an electronics unit 58 j,which are implemented as a coil module 144 j. FIG. 17 shows a sectionalview along a section plane II of coil module 144 j shown in FIG. 16. Apart of hand-held power tool rechargeable battery pack 40 j forms ahousing unit 42 j of inductive charging coil device 10 j having apocket-like receptacle area 104 j, which is situated in a base part 102j, for coil module 144 j having coil unit 12 j, core unit 14 j, andelectronics unit 58 j. Coil unit 12 j of coil module 144 j is formed bya printed circuit board 152 j, which has conductor layers 154 j on bothsides, which form printed conductors. The printed conductors formconductor loops 156 j of coil unit 12 j, which have windings on bothsides, and have a shared winding direction around a winding axis 56 j.The two conductor loops 156 j are connected to a connecting lead (notshown in greater detail), so that the two conductor loops 156 jelectrically form a coil. Core unit 14 j is formed by core elements 16j, which are connected using a binder 22 j, and covers coil unit 12 j.Core elements 16 j are predominantly made of a ferrite material.Electronics unit 58 j is situated adjoining core unit 14 j, edges 148 jof electronics unit 58 j protruding beyond coil unit 12 j and core unit14 j. Coil unit 12 j and electronics unit 58 j are connected using aconnecting lead (not shown in greater detail), which is led through coreunit 14 j. Receptacle area 104 j is provided to accommodate coil module144 j in an insertion direction 136 j, which is aligned in parallel to amain surface extension 138 j of coil unit 12 j, core unit 14 j, andelectronics unit 58 j. Two guide rails 146 j, which are situated inparallel to insertion direction 136 j, are situated in receptacle area104 j in such a way that two edges 148 j of electronics unit 58 j may beinserted into guide rails 146 j in insertion direction 136 j. Edges 148j are formed by a printed circuit board 52 j of electronics unit 58 j,which includes charging electronics. Edges 148 j are situated onopposite sides of receptacle area 104 j in relation to a directionparallel to main surface extension 138 j and perpendicular to insertiondirection 136 j. Main surfaces 140 j of receptacle area 104 j areimplemented as closed. An assembly opening 150 j, through which coilmodule 144 j is inserted in insertion direction 136 j, is closed by acover (not shown in greater detail) after assembly of inductive chargingcoil device 10 j. A cell unit 44 j of hand-held power tool rechargeablebattery pack 40 j is situated on a side of hand-held power toolrechargeable battery pack 40 j opposite base part 102 j, which has coilmodule 144 j. Hand-held power tool rechargeable battery pack 40 j isconnected after installation of coil module 144 j with the aid of aconnecting lead (not shown in greater detail) to charging electronics ofelectronics unit 58 j. Coil module 144 j is potted using an epoxy resin158 j in receptacle area 104 j after assembly for fixing and forprotection from environmental influences (FIG. 18).

Cell unit 44 j forms an assembly 142 j, which is to be shielded toprevent loss currents induced by an electromagnetic field in cell unit44 j required for operating inductive charging coil device 10 j. Forshielding, a shielding unit 108 j is provided, which is formed by amaterial layer 110 j, which has a projection area 112 j in the case of aprojection in the direction of winding axis 56 j of coil unit 12 j,which essentially covers cell unit 44 j. Material layer 110 j is formedby an electrically conductive lacquer layer, which is applied to apartition wall 160 j, which separates receptacle area 104 j from cellunit 44 j.

To charge cell unit 44 j, hand-held power tool rechargeable battery pack40 j is placed on a hand-held power tool device 38′j (FIG. 18), which isimplemented as a hand-held power tool rechargeable battery chargingdevice 72′j, and which includes a similarly constructed inductivecharging coil device 10′j. Hand-held power tool rechargeable batterycharging device 72′j has a current supply 74′j. If hand-held power toolrechargeable battery charging device 72′j is supplied with current, ahigh-frequency alternating current of 100 kHz, which is generated bycharging electronics situated on electronics unit 58′j, flows throughinductive charging coil device 10′j. A magnetic alternating field isgenerated in coil unit 12′j, which is focussed by core unit 14′j andemitted essentially in the direction of inductive charging coil device10 j. A current, using which cell unit 44 j may be charged, is inducedin coil unit 12 j of inductive charging coil device 10 j.

FIG. 19 shows a coil module 144 k of an inductive charging coil device10 k in a second exemplary embodiment. Coil module 144 k differs fromcoil module 144 j of the first exemplary embodiment in particular inthat a coil unit 12 k and an electronics unit 58 k are partiallyembedded in a core unit 14 k. Core unit 14 k is formed by core elements16 k, which are implemented as fragments of a ferrite material, embeddedin a binder 22 k. A core material composition, which is formed by aratio of binder 22 k and core elements 16 k, differs in areas 28 k ofcore unit 14 k. Core unit 14 k has a first, ring-shaped area 28 k, whichis formed by an area of higher density 86 k having a relativepermeability μ=200, in the direction of a winding axis 56 k, adjoiningconductor loops 156 k of coil unit 12 k formed by a printed circuitboard. Ring-shaped areas of moderate density 88 k of core materialhaving a relative permeability μ=50, adjoin this area of high density 86k on the inside and outside in relation to winding axis 56 k. On theoutside and inside, core unit 14 k is delimited by areas 28 k, which areformed by areas of low density 90 k. Electronics unit 58 k and coil unit12 k are situated on both sides of areas 28 k in relation to windingaxis 56 k and also potted using binder 22 k of core unit 14 k during themanufacturing of core unit 14 k. Coil unit 12 k and electronics unit 58k are partially embedded in core unit 14 k and form coil module 144 k. Aconductive material layer 110 k having a projection area 112 k, whichcovers electronics unit 58 k in the case of a projection in thedirection of winding axis 56 k, is situated on a side of electronicsunit 58 k facing toward coil unit 12 k. Material layer 110 k forms ashielding unit 108 k, which shields an electromagnetic alternating fieldoriginating from coil unit 12 k in relation to electronics unit 58 k,which forms an assembly 142 k to be shielded.

Coil module 144 k is provided, as in the first exemplary embodiment, tobe inserted into a pocket-like receptacle area of a housing unit in aninsertion direction to form an inductive charging coil device 10 k.

1-13. (canceled)
 14. An inductive charging coil device, comprising: atleast one coil unit; and at least one core unit; wherein the core unitis at least partially formed by microscopic core elements embedded in abinder.
 15. An inductive charging coil device, comprising: at least onecoil unit; and at least one core unit; wherein the core unit has aplurality of core elements, which are at least partially formed bysintered fragments.
 16. The inductive charging coil device of claim 14,wherein the core unit has a core jacket, which is provided for fixingthe core elements.
 17. An inductive charging coil device, comprising: atleast one coil unit; and at least one core unit; wherein the core unithas areas having a differing core material composition.
 18. Theinductive charging coil device of claim 14, wherein the core unit has atleast two core materials, which have differing permeabilities.
 19. Theinductive charging coil device of claim 14, wherein the core unit has atleast two core materials, which have at least one of differing densitiesand moduli of elasticity.
 20. The inductive charging coil device ofclaim 17, wherein at least two areas, having a differing core materialcomposition in a thickness direction of the core unit, form layerssituated adjacent to one another.
 21. The inductive charging coil deviceof claim 17, wherein at least two areas having a differing core materialcomposition are situated radially around a winding axis of the coilunit.
 22. The inductive charging coil device of claim 14, furthercomprising: a housing unit, into which the core unit is at least one ofcast and injection molded.
 23. The inductive charging coil device ofclaim 14, further comprising: a housing unit having a pocket-likereceptacle area for at least one of the coil unit, the core unit, and anelectronics unit.
 24. A system, comprising: at least two inductivecharging coil devices, wherein each of the inductive charging coildevices includes at least one coil unit and at least one core unit;wherein the core unit of at least one of the inductive charging coildevices has a plurality of core elements, which are at least partiallyformed by sintered fragments, and wherein the core elements have a meandiameter, which is at least 10 μm multiplied by a ratio of a corediameter of the core unit divided by an air gap in at least oneoperating state of the inductive charging coil devices.
 25. A method formanufacturing a core unit of an inductive charging coil device, thedevice including at least one coil unit and the core unit, the methodcomprising: at least partially forming the core unit by microscopic coreelements embedded in a binder.
 26. The inductive charging coil device ofclaim 14, wherein the inductive charging coil device includes ahand-held power tool inductive charging coil device.
 27. The inductivecharging coil device of claim 15, wherein the inductive charging coildevice includes a hand-held power tool inductive charging coil device.28. The inductive charging coil device of claim 17, wherein theinductive charging coil device includes a hand-held power tool inductivecharging coil device.
 29. A hand-held power tool device, comprising: aninductive charging coil device, including at least one coil unit and atleast one core unit, wherein the core unit is at least partially formedby microscopic core elements embedded in a binder.
 30. A hand-held powertool device, comprising: an inductive charging coil device, including atleast one coil unit and at least one core unit, wherein the core unithas a plurality of core elements, which are at least partially formed bysintered fragments.
 31. A hand-held power tool device, comprising: aninductive charging coil device, including at least one coil unit and atleast one core unit, wherein the core unit has areas having a differingcore material composition.